How did America's fight against communism affect the U.S. (1946-1990)?

In my opinion, the main impact of the fight against communism was that it served to weaken the US in terms of its ideals. I think that the US had to retreat from its ideals a bit just as it is having to retreat from its ideals today in the "War on Terror." I am not saying the US should not have fought communism, I am just saying that this is an impact.

The Cold War weakened our ideals in a couple of ways:

First, it weakened our dedication to free speech and freedom of expression. For parts of the Cold War, dissent was equated with lack of patriotism or with out-and-out treason. We came to think that Americans had to think/believe certain things. This is not in accordance with our ideals.

At the same time, it weakened our dedication to supporting human rights and democracy around the world. During the Cold War, we supported all sorts of nasty governments simply because they were not communist. By doing so, we backed away from the idea that we should act according to our ideals of freedom and liberty -- that we should try to bring those to people around the world.